there is a very good con that happens in some similar circumstances, but it's mainly people who buy new developments as flats who suffer

the properties are "vauled" higher by 10-20%
the peole flogging them then say that they will pay the stamp duty and/or a 10-15% deposit on your property as an incentive

you then go to the bank and say "i've got a property worth (for example and to make the numbers easy) £100,000 and i need an 85% mortgage" because the seller is paying your 15% deposit

when you actually buy the property and move in and ask around, the "real value" is actually £60k and your wonderful price has now got you into a shit load of trouble

the way they get around it is that they sell the property for the full price as reported to the land regestry peole, so that makes it "legal" for the £100k price tag and the explosion of prices continues in that development

as the person who's been screwed the only thing you can do to generate a garanteed income on the property is rent it out, but because you can only rent it out at it's vaule of £60k you get scummy tenants and the whole development drops vaule even more

the only ones who have made any money are the developers who are crafty fuckers at the best of times